The present invention relates to a method and apparatus for detecting and monitoring the growth of microorganisms which are shielded from the measuring device. The microbial growth is detected and monitored by measuring the difference in potential between two electrodes maintained in fluid or gaseous contact with the microorganisms, but kept from physical contact by a semipermeable barrier.
in microbiology, the indirect or remote detection of cell growth is desirable when conditions do not favor direct contact of the probe or sensor with the organisms or precludes physical manipulation of the cellular elements. Absence of contact between the microorganisms and the detecting device is especially advantageous when handling highly infectious organisms. Furthermore, direct contact between the sensor and the microorganisms could impede or alter the organisms' biochemical processes. The presence of the sensor in contact with the microorganisms would add a variable which would have to be considered in the interpretation of data. A measuring device which is in contact with microbial growth would have to be sterilized after each use. These are some of the handicaps which can be eliminated by using the indirect apparatus and method of detection of the present invention.